Field
This application relates generally to exhaust impingement cooling and the reduction of heating effects of an exhaust plume on an impinged surface.
Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 1.98
Reducing excessive heating effects of exhaust systems presents a major challenge for next-generation air vehicle systems. Tomorrow's air vehicles will be required to manage increasing levels of thermal, mechanical, and electrical power. This need arises from demands for advanced propulsion, aerodynamics, sensor, and weapon/payload capability necessary to defeat threats, perform with greater fuel efficiency, reduce noise and emissions, and decrease life cycle cost.
Emerging technologies of interest, such as advanced engines, high power sensors, directed energy weapons, and enhanced electronic actuation, will require much more power than today's systems. The heat load generated from these emerging power system technologies will need to be removed from an air vehicle using one or more exhaust nozzles.
While demand for power management functionality grows, there is also an emerging design trend toward embedding or highly integrating propulsion and power systems such that exhaust apertures are directed downward from a vehicle. This trend will likely present airframe designers with significant challenges in meeting heating constraints driven by peak allowable temperatures for impinged surfaces (limited by tarmac/runway material temperature limits).
There is also an emerging design trend toward embedding or highly integrating propulsion and power systems such that exhaust apertures are directed upward from a vehicle such that peak allowable temperatures for adjacent upper aircraft component surfaces, limited by adjacent airframe composite materials, for example; becomes an issue.